Computers are used in many applications. To position a cursor on a computer display and/or to enter commands, a computer pointing device is typically used. Pointing devices have been developed for two different interface types within the host computer. Until recently, both interface types required a specialized computer pointing device. For example, a pointing device such as a mouse was introduced in a version operable with a RS-232 interface on the computer, and also in a separate version operable with a PS/2 or mouse port interface on the computer. Subsequently, combination pointing devices, capable of operation with more than one type of interface, were introduced. The combination pointing device was connected directly to the PS/2 port by a wire cable and to the serial port by the wire cable and an adaptor. However, in some applications the combination pointing devices must have the capability of sharing the use of wires in the wire cable depending on the type of interface to which they are connected. Therefore, it can be appreciated that there is a significant need for a combination computer pointing device that automatically shares the use of wires depending on the interface type to which it is connected. The present invention provides this and other advantages as will be illustrated by the following description and accompanying figures.